As a full-face-type helmet in which a ventilator mechanism is provided to a head protecting body to ventilate the interior of the head protecting body as described above, for example, one described in U.S. Pat. No. 6,263,513 is conventionally known. The full-face-type helmet of U.S. Pat. No. 6,263,513 comprises a head central/rear ventilator mechanism at a head central/rear region including the vertex region (the vertex region substantially opposes the vertex of the wearer) and the upper portion of the back head region (the back head region substantially opposes the back part of the head of the wearer) of the head protecting body.
The head central/rear ventilator mechanism provided to the helmet of U.S. Pat. No. 6,263,513 comprises:
(a) a pair of left and right shutter members which reciprocate to open/close vent ports,
(b) three left, three right (a total of six) shutter attaching members respectively held at predetermined positions of the head protecting body to attach and hold the shutter members reciprocally, and
(c) a cover/air current deflecting member held at a predetermined position on the outer surface of the head protecting body in order to cover the shutter members and shutter attaching members and to deflect an air current flowing relatively along the outer surface of an outer shell so as to stabilize the head protecting body.
In this case, the cover/air current deflecting member is attached and fixed to the outer surface of the head protecting body by adhesion with an adhesive or a double-sided tape, or by fastening with a screw or rivet. The shutter attaching members are attached and fixed to the head protecting body by fitting their fitting cylindrical portions in exhaust holes formed in the head protecting body.
In the head central/rear ventilator mechanism of U.S. Pat. No. 6,263,513, the shutter members can open/close the through holes (in other words, exhaust holes formed in the head protecting body) of the respective fitting cylindrical portions of the shutter attaching members. Therefore, in the helmet of U.S. Pat. No. 6,263,513, when necessary, internal air can be led from the interior of the head protecting body (that is, from the inner structure of the head protecting body itself and/or the head accommodating space of the head protecting body) to the outside. When the internal air is led out in this manner, the interior of the head protecting body can be ventilated well.
In the helmet of U.S. Pat. No. 6,263,513, in order that the cover/air current deflecting member covers well the shutter members and shutter attaching members configured to ventilate the interior of the head protecting body and deflects the air current well so as to stabilize the head protecting body well, a comparatively large projection portion and recess portion must be formed on the cover/air current deflecting member. Such a big projection portion projects outward from the outer surface of the head protecting body. Therefore, for example, if the helmet of U.S. Pat. No. 6,263,513 is used as an off-road driving helmet for a motocross where falling accidents occur comparatively often, when an unforeseen circumstance such as a fall of a motorcycle during driving occurs, the comparatively large projection portion on the cover/air current deflecting member may catch on the ground surface of the unpaved road or a wasteland. Then, the head protecting body of the helmet may not function to skid smoothly on the ground surface of the unpaved road or the wasteland substantially in the traveling direction of the motorcycle so as to moderate the degree of injury or the like of the wearer. Hence, in the case of the helmet of U.S. Pat. No. 6,263,513, for example, when the motorcycle falls, the degree of the injury of wearer may not be able to be moderated due to the presence of the head central/rear ventilator (particularly its cover/air current deflecting member).